The optical disc device is now in widespread use in personal computers. Recently, the thickness of the optical disc device is reduced and is set in laptops. According to the slim-type optical disc device, the solenoid is usually used to be a power of the ejection mechanism of the tray. Referring to FIG. 1, FIG. 2, FIG. 3, FIG. 4, and FIG. 5, schematic diagrams of a conventional lock mechanism of a tray and the lock mechanism at different states are illustrated. Referring to FIG. 1 and FIG. 2, the conventional lock mechanism comprises a tray 11, a locking element 12, a solenoid 13, a linked apparatus 14, a first arm 15, and a boss 16. The locking element 12 is connected with a first elastic device 121 that is rotably fixed on the tray 11. The solenoid 13 is fixed on the tray 11 to provide a magnetic force and includes an active block 131 which is set in a side of the solenoid 13. The linked apparatus 14 is connected with the active block 131 and is rotably fixed on the tray 11 to push the locking element 12. The first arm 15 is rotably fixed on the tray 11 to push the linked apparatus 14 and is connected with a third elastic device 151 which provides a force on the first arm 15. The boss 16 cooperates with a hook part 122 of the locking element 12. As shown in FIG. 2, the linked apparatus 14 of the conventional lock mechanism comprises a second arm 141 and a second elastic device 142 with reciprocal linking. A first end 1411 of the second arm 141 is connected with the active block 131. A second end 1412 of the second arm 141 is rotably fixed on the tray 11. A third end 1413 of the second arm 141 is linked the locking element 12. The second elastic device 142 is connected with the second arm 141 and is pushed by the first arm 15. By the way mentioned above, the tray of optical disc device can be loaded and ejected with a disc placed on it.
Referring to FIG. 3, a schematic diagram of a conventional lock mechanism at the ejection state is illustrated. The solenoid is normally kept to have a magnetic force in this illustration. When the magnetic force of the solenoid 13 is removed, the active block 131 parallely springs toward a direction 31 so that the second arm 141 of the linked apparatus 14 then rotates to push the locking element 12 to move toward a direction 32 that enables the hook part 122 of the locking element 12 to depart from the boss 16. Therefore, the tray 11 can be ejected by a force of a compression spring (not shown in FIG. 3).
Referring to FIG. 4 and FIG. 5, schematic diagrams of the conventional lock mechanism during tray loading process are illustrated. As shown in FIG. 4, when a user would like to load a CD, the tray 11 can be moved toward a direction 41 that enables the boss 16 to push the first arm 15. The first arm 15 then pushes the second elastic device 142 of the linked apparatus 14, and the linked second arm 141 drives the active block 131 to move toward the inside of the solenoid 13. In another word, the active block 131 can be inhaled by the solenoid 13 again. In the process, the boss 16 departs from the first arm 15 at first. The first arm 15 is sprung back by the pulling force generated from the third elastic device 151. Referring to FIG. 5, because the active block 131 is inhaled by the solenoid 13, the second arm 142 of the linked apparatus 14 releases the locking element 12. The locking element 12 is sprung back by the pulling force generated from the first elastic device 121 that enables the hook part 122 of the locking element 12 to cooperate with the boss 16 again to finish the loading.
In the loading process, the lock mechanism will be producing two sounds, a first sound is a sound generated by the first arm 15 being sprung back and a second sound is a sound generated by the locking element 12 being sprung back. When users hear the first sound, they may feel that the locking element has cooperated already. However, the reality is that the locking element does not cooperate with the boss completely that may confuse users. Hence, there must be some ways to resolve the problem mentioned above by providing a lock mechanism to be a total solution.